Method and apparatus for making antifriction bearings with locking cams



Sept. 27, 1966 .ROEME 3,274

R METHOD AND AP ATUS FOR MAKING ANTIFRICTION BEA GS WITH KING CAMS 'led Jan. 1965 In ventor ER/CH ROM/5R United States Patent 3,274,815 METHOD AND APPARATUS FOR MAKING ANTI- FRICTION BEARINGS WITH LOCKING CAMS Erich Roemer, 'Kapellenstrasse 60, Wiesbaden 62, Germany Filed Jan. 25, 1965, Ser. No. 427,782 Claims priority, application Germany, Feb. 1, 1964, G 39,759 7 Claims. (Cl. 72-152) The invention relates to the manufacture of antifriction bearings with locking cams or lugs.

Heretofore, locking or retainer cams, lugs and the like were generally formed on completely shaped bearings by stamping or other suitable pressing tools which were equipped with knives or cutters and operated in a hammering or stamping press. After the bearings had been stamped they still had to be machined for finishing the running surface. This stamping had to be carried out in a separate working stage, which made the production of the bearings more expensive and moreover necessitated internal refinishing since the stamping damaged the running surface of the bearing which had already undergone the final processing. The known method of stamping the cams could therefore only be combined with the known method of producing the antifriction bearings in which the bearings were formed by rolling from either strip material or blanks cut to size in advance, if a chip-removing or finishing processing of the running surfaces were introduced after the forming process.

The object of the invention is therefore to provide an improved method and apparatus for producing locking cam-s or lugs on anifriction bearings, which can be used in any method for producing the actual bearings and no longer necessitate any finishing treatment of the running surfaces after the formation of the locking cams or lugs.

This is accomplished according to the invention in that the locking or holding cams are cut and pressed into their final shape in the gap or nip between a pair of rolls with the aid of at least one knife and the pressure exerted by said rolls. This not only accelerates and simplifies considerably the formation of the locking cams, but also the running surface of the bearing itself, even in the direct vicinity of the knife producing the locking cams, is saved by the roll acting on this surface to such an extent that subsequent surface treatment is no longer necessary. According to the invention, the stage effecting the formation of the locking cams can very easily and simply be incorporated in any conceivable process for making antifriction bearings.

It is particularly advantageous according to the invention to effect the incising and pressing of the locking cams at the trailing end of the bearing as it travels between the rolls. Due to the fact that the locking cam is cut in the end of the bearing which is firmly clamped between the two rolls, the formation of a properly shaped locking cam is assured.

Another particular advantage is attained according to the invention by forming the locking cams simultaneously with the final rolling in a rolling process for producing the bearing itself.

This results in a particularly favorable incorporation of the cam forming stage in the process of producing the anti-friction bearings themselves.

For carrying out the method according to the invention an apparatus is provided comprising a pair of rolls, wherein the roll which faces towards or engages the interior of the bearing carries at least one knife which projects beyond the circumference of the roll at the place where the locking cam is to be produced, whereas the counter-roll which is driven synchronously with the first-mentioned roll has in its peripheral surface recesses corresponding to the locking cam to be produced, or to the knives, and provided with at least one cutting side edge. In order to ensure that the locking cams are very accurately positioned, a supporting or positioning element for the forward or leading parting surface of the bearing blank is arranged on the surface of the roll acting on the inner side of the blank and the knife for forming the locking cam is arranged opposite this supporting element so that it engages the rear or trailing end edge of the bearing.

For forming the locking cam during the production of the bearing itself it is particularly advantageous if the pair of rolls is constructed at the same time as device for the finish rolling of the antifriction bearing, if necessary with reduction of the wall thickness.

A preferred embodiment of the invention is hereinafter described in greater detail by way of example with reference to the accompanying drawing, in which FIGURE 1 is a diagrammatic perspective view showing a portion of an antifriction bearing with locking cam and bearing housing provided with notches, and

FIGURE 2 is a diagrammatic representation of the apparatus for producing antifriction bearings and at the same time forming the locking cam thereon.

As FIGURE 1 shows, the bearing 1 is provided at least at one of its parting surfaces 2 with a locking cam 3 which is formed by pressing outwards a portion of the wall of the bearing 1. This locking cam 3 engages in a notch 5 in the bore of the bearing housing 4 when inserting the bearing 1. The parting surface 2 in the region of the locking cam 3 then lies in the plane of the parting surface 6 of the bearing housing 4 and bears against the full or unbroken parting surface of the second bearing half (not shown). Any twisting of the bearing within the housing bore is thus prevented.

The example for the production of locking cams illustrated in FIGURE 2 involves a rolling method and a rolling apparatus for the production of antifriction bearings. Here the blank 11 is guided through the nip or gap be tween the two rolls 12 and 13, the wall thickness of the blank 1 1 being reduced in the process.

When introducing the blank 11 into the roll gap it is brought into contact with an abutment 14 on the periphery of the roll 12 coordinated to the coated side of the blank 1-1. This abutment is, in the example illustrated, in the form of a bar or strip extending axially across the periphery of the roll and projecting therefrom. It is, however, also possible to construct the abutment in the form of a claw which is mounted in the roll 12 and approximately radially retractible therein. In the example illustrated, it is also possible to provide a pair of lateral holding claws (not shown) which cooperate with the abutment 14 when the blank introduced is to be held so that it rests firmly on the surface of the roll 12 and is in contact with the abutment 1-4. Such alternative constructions are shown in my copending application Serial No. 427,783, entitled Method and Device for Rolling Thinwall Bearings, and filed on the same date, January 25, 1965, as the present application.

A knife 15, which corresponds in its width to the locking cam to be formed, is mounted in the roll 12 approximately diametrically opposite the abutment 14 in such a way that it corresponds in its arrangement to the position of the locking cam 3 to be formed. This knife 15 is of triangular cross-section and projects from the circumference of the roll 12. In width it corresponds to the width of the locking cam to be formed. At its two sides it is fashioned into cutting edges, between which lies the substantially level forming surface with which it presses a portion of the blank outwards thereby producing the locking cam 3. The forming surface between the cutting edges projects from the roll 12 at an angle which is larger than the angle between the circumference and a tangent at the point of projection of the knife.

In the counter-roll 13, which is driven synchronously with the roll 12, there is a recess 16, the side edges of which are likewise constructed as cutting edges and which is of a Width corresponding to the outer width of the locking cam 3. If a holding claw retractible substantially radially in the roll 12 is employed instead of the abutment 1 4, the counter-roll 13 is provided with a second recess approximately diametrically opposite the recess '16 for receiving the holding claw.

As the rolls 12 and 13 rotate, the blank is incised at its trailing end by the knife 15 and formed into the locking cam 3. Due to the fact that the cutting edges of the knife '15 and the forming surface between them extend away from the periphery of the roll 12 at an angle greater than that formed by the tangent, the cutting and forming of the locking cam 3 commences at the rear or trailing edge of the blank. The cutting direction is there- .fore counter to the direction of movement of the blank during the rolling process, that is extends from the rear or trailing edge towards the front or leading edge of the blank. If the Wall thickness of the blank 11 is reduced during the rolling process, the length of the blank will be increased with the result that the rear end of the blank 11 in the region of the locking cam 3 to be formed is pushed slightly in longitudinal direction over the cutting edges of the knife 15, thereby facilitating the cutting operation and the shaping of the locking cam.

In order to assure the accurate lateral location of the locking cam 3, the abutment 14 may be in the form of an angle, thus enabling the blank to bear accurately with its front edge as well as its lateral edge.

The method and apparatus according to the invention are particularly advantageous also when the locking earn 3 is located at the extreme side edge of the blank, in which case only one cut is necessary. The rolls 12, 13 and the knife 15 can then be of considerably simpler construction. The forming surface of the knife in this case is generally not level.

According to the invention it is quite possible to feed into the gap between the rolls 12 and 13 bearings previously produced by some other method, for which purpose a feeding device adapted to the shape of the prepared bearings will have to be provided which introduces the bearings on which the locking cams 3 are to be formed so that one of their parting surfaces bears against the abutment 14.

All the characteristics set forth in the above description and the appended claims and illustrated in the accompanying drawing may be of significant importance to the invention either individually or in any conceivable combination.

I claim:

1. The method of making an antifriction bearing with an outwardly displaced segment in its wall at the parting line, consisting in passing the blank between pressure rolls which apply pressures to opposite sides of the blank, in-

cising the wall of the blank at the parting line thereof with at least one knife and displacing outward the incised wall portion into a recess in one of said pressure rolls.

2. The method of claim 1, wherein the incising and displacing of the wall of the bearing blank is effected at the trailing edge thereof.

3. The method of claim 1, wherein the blank is reduced in thickness as it passes between the pressure rolls.

4. Apparatus for producing a locking cam on a bearing the parting line thereof, comprising in combination:

(a) a pair of cooperable synchronized pressure rolls arranged axially parallel to each other, one roll being adapted for acting on the inner side of the bearing blank,

(b) a knife on said roll for incising the wall of the blank, said knife projecting beyond the circumference of the roll to effect an outward displacement of the incised wall,

(c) the other roll having a recess arranged to travel opposite said knife and in which the incised wall of the bearing blank is received as the blank passes between the rolls.

5. An apparatus as in claim 4, wherein:

(a) the said one roll has an abutment for engagement with one parting surface of the blank constituting the leading edge thereof as the blank passes between the rolls, thereby to position the blank with respect to the knife,

(b) said knife being disposed with respect to the abutment to engage the trailing edge of the blank for effecting the incising at said trailing edge.

6. Apparatus as in claim 4, wherein:

(a) the knife projects from the said one roll at an angle which is larger than the angle between the circumference and a tangent at the point of projection of the knife.

7. Apparatus as in claim 4, wherein:

(a) the pressure rolls are sufficiently heavy to effect a reduction in the thickness of the blank,

(b) said one roll having a surface adapted to finish the inner side of the blank.

References Cited by the Examiner UNITED STATES PATENTS JOHN F. CAMPBELL, Primary Examiner.

THOMAS H. EAGER, Examiner. 

1. THE METHOD OF MAKING AN ANTIFRICTION BEARING WITH AN OUTWARDLY DISPLACED SEGMENT IN ITS WALL AT THE PARTING LINE, CONSISITING IN PASSING THE BLANK BETWEEN PRESSURE ROLLS WHICH APPLY PRESSURES TO OPPOSITE SIDES OF THE BLANK, INCISING THE WALL OF THE BLANK AT THE PARTING LINE THEREOF WITH A LEAST ONE KNIFE AND DISPLACING OUTWARD THE INCISED WALL PORTION INTO A RECESS IN ONE OF SAID PRESSURE ROLLS. 